Abstract:
A hydraulic control system for linear actuation that provides a bypass flow during startup of a lifting command, provides a split flow between a cylinder and a reservoir once a minimum operating speed of a pump has been reached, and provides complete flow to a cylinder after the minimum operating speed of the pump has been reached. This is achieved through control of a flow control valve and a proportional flow control valve by a processor.
Abstract:
The invention relates to a method (25) of determining the health status of a hydraulic circuit arrangement comprising at least one hydraulic fluid working machine (2, 3). The health status is determined (29) using at least in part an actual temperature information (12) of the hydraulic circuit arrangement (1) that is compared to an expected temperature information (24) of the hydraulic circuit arrangement (1).
Abstract:
A servo piston assembly (10) having a servo piston body mounted within a servo piston cylinder (32). A pair of bushings (34) are mounted within each end of the servo piston body. An elongated bore (38) extends through the servo piston body and receives a guide rod (36) that extends out of the servo piston body and is received within the servo piston cylinder (32).
Abstract:
A pump control system, comprising: a motor (12) configured to drive a pump (14); a pressure relief valve (22) in fluid communication with the pump (14); a torque control valve (32) connected to a swashplate of the pump (14) and in fluid communication with the pressure relief valve (22); a swashplate angle sensor (36) connected to the swashplate (34); and a computer (40) connected to the swashplate angle sensor (36) and the pressure relief valve (22) wherein the computer (40) controls the pressure relief valve (22) based upon swashplate displacement to achieve maximum system pressure. The corresponding method of controlling is also disclosed.
Abstract:
A hydraulic circuit arrangement includes a plurality of electronically- commutated pumps (10a-10f) providing flow to a common hydraulic line (65), each of the electronically-commutated pumps provided with an associated electronically-commutated pump controller (18a-18f). The plurality of electronically-commutated pumps (10a-10f) includes one or more quantized electronically-commutated pumps and one or more unquantized electronically-commutated pumps, wherein the one or more quantized electronically-commutated pumps (10a) are configured to produce a quantized target flow value that is less than a total target flow value determined for the common hydraulic line, and wherein the one or more unquantized electronically-commutated pumps (10b) are configured to produce an unquantized target flow value that is the difference between the quantized target flow value and the total target flow value.
Abstract:
Hydraulic fan system and method for controlling the speed of a hydraulic fan system. The fan system comprises a fan operated by a hydraulic motor which is driven by a hydraulic variable displacement pump comprising a displacement volume adjusting element. A tilt angle of the displacement volume adjusting element can be adjusted by controlling a tilt current supplied to an electronic displacement control unit. The hydraulic fan system further comprises means for determining the volumetric flow rate of the pump and a control unit comprising: a signal connection to the means for determining the volumetric flow rate of the pump, a signal connection to a fan speed setting device, and a fan speed calculating unit for calculating a fan speed from the determined volumetric flow rate, a fan speed error determining unit for determining a fan speed error by comparing the calculated fan speed to the fan speed set by the fan speed setting device. The control unit can supply an adapted tilt current to the electronic displacement control unit in order to adjust the tilt angle of the displacement volume adjusting device, such that the volumetric flow rate can be adapted in order to reduce the fan speed error, wherein an ideal tilt current value is derived from the calculated fan speed and safety actions are performed in order to prevent damage to the fan, if the difference between the ideal tilt current value and the adapted tilt current is higher than a tilt current threshold value.
Abstract:
A hydraulic control system for linear actuation that includes an electric motor connected to a hydraulic pump and a hydraulic cylinder connected to the pump by a first flow line. A pressure transducer, a pressure control valve, and a check valve are connected to the first flow line between the pump and the cylinder and a tank is connected to the pump by a second flow line and the cylinder by a return line. A control valve is connected between the first flow line and the return line.
Abstract:
A system and method for secure remote control of a machine includes transmitting video data from a camera on the machine to an operator controller located at a remote operation station, and receiving, at a machine controller of the machine, an operator control message from the operator controller. The operator control message is based on an input device actuated in response to the video data. The method further includes confirming validity of the operator control message based, at least in part, on the video data transmitted from the camera to the operator controller, and controlling the machine with the operator control message when validity of the operator control message is confirmed.
Abstract:
The invention relates to a method (19) of operating a hydraulic arrangement (1) including a mounting base (5), a boom (3) that is pivotably arranged on the mounting base (5), and a Z-kinematics (2) that is arranged on the boom (3). The Z-kinematics (2) tilts a tool attachment device (10), that is pivotably arranged on the boom (3). The boom (3) is moved by a lifting hydraulic piston (7) that is connected to the boom (3) and to the mounting base (5). The Z-kinematics (2) is moved by at least a tilting hydraulic piston (11) that is connected to a lever of the Z-kinematics (2) and to the mounting base (5). On application of an input control command for changing the position of the lifting hydraulic piston (7), a compensation command is automatically generated and applied to the tilting hydraulic piston (11), to essentially maintain the attitude of the tool attachment device (10). The compensation command is generated based on the input control command for the lifting hydraulic piston (7), using a mathematical model of the hydraulic arrangement (1).